1. Technical Field of the Invention
The present invention relates to a therapeutic method and an endoscopic system which use an overtube, and in particular, to the therapeutic method and the endoscopic system which use an overture and which are preferable to treatment on endoscopic retrograde cholangiopancreatography (ERCP) with patients who had a Roux-en-Y reconstructive operation.
2. Related Art
Endoscopic examinations and treatments for biliary disease and pancreas disease, such as biliary tract cancer, pancreas cancer, cholelithiasis, and common bile duct stone, are progressing at a rapid pace. Compared to the conventional surgical treatments, these examinations and treatments are less invasive and less burden on patients. The techniques for these examinations and treatments include endoscopic retrograde cholangiopancreatography (ERCP) and Endoscopic sphincterotomy. These endoscopic examinations and treatments are on the progress to applications to postgastrectomy cases.
The difficulty level of procedures largely depends on reconstruction performed after partial removal of the stomach or reconstruction performed after the total gastric resection. As to the procedural difficulty level after the stomach reception, a Billroth I reconstruction can be performed using the normal ERCP procedure. Meanwhile, in a Billroth II reconstruction and in the reconstruction performed after the total gastric resection, it has been considered that the procedure related to the ERCP is higher in the difficulty level.
The Roux-en-Y reconstructive operation is most frequently used as the reconstructive operation for the total gastric resection. In the following references, reported is a successful example of ERCP which uses an endoscope-dedicated overtube for the small intestine in the treatment of the common biliary duct stone on the Roux-en-Y reconstructive operation.    [Reference 1] Hirai et al., “An Oblique-viewing Endoscope with an Overtube Facilitate Bile Duct Stone Removal in Roux-en-Y Gastrectomy Patients,” Gastroenterological Endoscopy 2006; 48: 212-217.    [Reference 2] Satoh et al., “3 cases of endoscopic treatments of Roux-en-Y reconstructive stomach through papilla—Effectiveness of Oblique-viewing Endoscope and Small Intestine Overtube,” Therapeutic Research for Hepato-Biliary-Pancreatic Diseases, Vol. 4 No. 1, page 88, 2006.
These references show that the ERCP was performed with an oblique-viewing endoscope, in which the digestive tract was shortened by stretching operations of the endoscope, a small-intestine overtube was made to advance to suppress deformations of the digestive tract, and then the endoscope was made to advance. It is reported that, though being in all of a few cases, repeating these operations allowed to the endoscope to reach the duodenum papilla.
For using procedures with an oblique-viewing endoscope or a forward-viewing endoscope, it is easier to insert the endoscope into an object because the view in the inserting direction can be secured. However, in this case, it is difficult to perform treatment, because the view in the treating direction cannot be secured. Thus, it is easy for the endoscope to pass the overtube through the jejunum-anastomosed bent portion and to reach the papilla, while it is difficult to treat the papilla by the endoscope. If giving greater importance to easiness of the treatment of the papilla to the contrary, a side-viewing endoscope may be used. However, for the side-viewing endoscope, the view in the inserting direction cannot be secured, resulting in a lessened performance for inserting the endoscope. As stated, it is considerably difficult to make both the treatment and the inserting performance easier at the same time.